Western North Slope rig-move response enters final cleanup stage

Shore-seal boom is now the main line between the Western North Slope rig-move site and the surrounding tundra as the Doyon 26 response moves into its final cleanup stage near Nuiqsut. Unified Command says monthly status reports are continuing, and crews have used the boom to keep contamination from spreading off site and to stop clean snowmelt from running into the affected area. The latest check showed limited sheen inside the containment area, but none outside the boom, a sign that matters as spring breakup gives way to summer access on the North Slope.

The incident, listed by the Alaska Department of Environmental Conservation as Spill No. 26399902301, happened about 6.5 miles northwest of Nuiqsut on Jan. 23, 2026, beside a gravel road in the Alpine Field area. DEC said the Doyon 26 self-propelled drilling module left the road and toppled onto tundra covered in 12 to 24 inches of snow. The site was less than 500 feet from a tributary to the Nechelik Channel of the Colville River, with the nearest oil and gas infrastructure about 50 feet away and a pipeline about 202 feet away. DEC said the pipeline was not impacted.

Eight personnel were treated for minor injuries on the North Slope and released. DEC first estimated the release at about 4,000 gallons of diesel and 735 gallons of hydraulic oil, while Doyon later said crews recovered about 5,565 gallons of spilled product, more than the original 4,735-gallon estimate. Doyon also said 41 gallons of un-spilled ethylene glycol were removed from the rig’s coolant system. The company said the difference in volumes reflects flush-and-recovery conditions and product composition changes, not a larger release.

Doyon says Phase 3 now covers final cleanup, mitigation and remediation of the entire affected area, along with monitoring through spring breakup and sampling through the summer. Flush-and-recovery work continued through April 29, all heavy equipment was removed on or before April 28, and the ice road was decommissioned after the equipment came out. The cause remains unknown, and DEC says the investigation will begin when it is safe to do so.

The Doyon 26 rig, commissioned in 2016 and nicknamed “The Beast,” was being moved on behalf of ConocoPhillips when it toppled. Doyon says Unified Command includes the U.S. Environmental Protection Agency, DEC and the North Slope Borough, with the Iñupiat Community of the Arctic Slope supporting the incident management team. For Nuiqsut and nearby users watching the Colville corridor, the key test now is whether containment holds as thaw, runoff and summer travel intensify pressure on the site.